Field of the Invention
The present invention relates to a solid-state imaging apparatus, an imaging system, and a method for driving the solid-state imaging apparatus.
Description of the Related Art
A solid-state imaging apparatus of a complementary metal-oxide semiconductor (CMOS) or charge-coupled device (CCD) type includes photodiodes that perform photoelectric conversion. If a photodiode is shielded from light, a variation in black offset value will occur due to dark current during photoelectric conversion. The dark current significantly depends on temperature, so that the black offset value significantly varies over time. According to a known technique, a solid-state imaging apparatus is allowed to include pixels for receiving light and pixels shielded from light (hereinafter, “light-shielded pixels”) in order to correct a variation in black offset value and correct an image based on information obtained from the light-shielded pixels.
Japanese Patent Laid-Open No. 2005-130045 discloses a technique of extending a charge accumulation period for light-shielded pixels to increase the accuracy of dark current measurement in order to accurately estimate the temperature of an imaging device. Such an imaging apparatus accurately estimates the temperature of the imaging device, so that image processing can be changed depending on the temperature of the imaging device.